Antistain baths for color photographic materials



Patented Nov. 8, 1949 UNITED STAT ES.

,ANTISTAIN BATHS Eon copoa .PHQIOGBABHIO MATERIALS S udderMe key, B cn'& Film Corporation,

to General Aniline N. Y., assignor NewYork,

N. "Y., a -eorporation of Delaware No Drawing. Applicationluly 21, 1948,SeriaL .0; 0

4 Claims. 1

This inv n io relates to ph to a ic e sta n ba hs, to .antiestain 'ba hsmp oyed in mu ti lay r color p to raphy, a d esp c l y final rinse bathsfor the washing of multi-layer colo p oto aph c material .o in th fixintrea me t-s a to pr ent t iorma ion 0i stai I s vknown tha in herocessing o mul color reversible an mum-colo re ersible White op qu theex osed mm r exnosedr h te opaque, is first developed with a normalblack and white developer to produce a negative image. Afterdevelopment, the black and white negative material, without being fixed,is exposed to general illumination, followed by a second developmentwith a color forming developer. Duringthe first and second development,the silver-halides in all the layers are reduced to metallic silver.After the s c nd develo n he m i is cleared in running'water, hardenedin an aqueous solution consisting of either alum or potassium c om a umandt n as in unning water- Aiter the latter treatment, the silverpresent all the layers formed during the first and second d elo men isco v ted i a sa by and 9f the known silver-salt formers, as bleachingbaths, and the silver-salt $11311 iormedis then removed bydissolvingitin a silver-.- salt solvent such as, for example, hypo. Thematerial is then washed for .a long period of timeand then dried.

common y lsnown triazines contemplated for reaction with theformaldehyde have'the following formulae:

In'Formula l at least one Y is an amino group having at least onereactive hydrogen atom, the

remaining 'Ys being a radical such as hydrogen,

' amino, hydroxy, halogen, i. e., chlorine, bromine,

During the final washing operation 'itis essential that the residualsecond or :oolor developer and bleach solutions be removed, otherwisestains will be formed during the drying operation, which areparticularly noticeable in the white area. In

order to prevent this staining, an extended final washing time inrunning water of irom fifteen minutes to two hours has been proposed.Even if this proposal be adopted, stains arenevertheless. formed duringand after the drying operation. It is believed that the staining resultsfrom the oxidation of'traces ofthe color developer retained in thelayers of the material following color-forming eve o ment, w ich hen.rea t w th he amused colo imme An b e t of th present inve t on s t eiini nate excessive washing time of color developed inulti eetlorpotographic ma r a whi e p eve ngthe intimatio i tain.

. A iii-1 K 53? obj ct at th in ent n is finalrinee bath which clearsundesirable matter from a multi-color photographic material in a shorttime while avoiding staining.

Other objects and features of the invention ,Will become apparent as thedescription proceeds. I I have discovered that the above .pb'iects areaccomplished lay-employing as a final rinsebat-h -an aqueous solutioncontaining a small quantity of a water-soluble addition product :offormalde' h de a diazine riaz ne. The an T1. represents halogen,

methoxy, ethoxy, propoxy, I

etc., alkyl, i. e., methyl, ethyl, propyl, isopropyl, butyl, etc.,alkylene, i. e., l-butenyl, etc aryl, i. e., phenyl, naphthyl, etc., andaralkyl, -i. e., benzyl, methylbenzyl, ethylbenzyl, etc. 'InFormula 2 Zrepresents hydrogen, amino, alkyl, 1. e., methyl, ethyl,'-butyl, etc.,p'henyl, phenylenahydroxy, alkox-y, i. e., methoxy, ethoxy, propoxy,etc., mereapto, alkylthio (alkyl-S-), i. e., methylthio, ethylthio,propylthio, etc., and hydrazino, at least two Zs being primary amino orhydrazino. In Formula 3 X is hydrogen or a primary amino and Ihydrazino, "phenyl, hydroxy, alkoxy, i. e., butoxy, etc,, or analkylthio (alkyl-S-i group, i. e., methylthio, ethylthio, propylthio,etc.

The water-soluble addition products of formaldehyde and an azinecharacterized by Formula 1 are prepared according to the methodsdescribed in United States Patent 2,197,357. The water-soluble productswhile utilizing the azines of Formulae 2 and 3 are prepared according tothe methods described in United States Patents, 2,211,? 10 and2,211,709, respectively.

'By utilizing this final rinse bath, in lieu of extended washi in watethe washin time a e "fixing is considerably reduced, and stain formationprevented, The exact operation of the water-soluble addition products offormaldehyde and an azine in the final rinse bath is unknown and to datehas been unascertainable. it is known that the tendency to stainformation encountered in the processing of color film by the colggprforming development method is attributable 3 in the main to theretention in the layers of the multi-layer material of small amount ofthe color developer. This becomes progressively oxidized by atmosphericconditions, the oxidized products reacting with unused and unremovedcolor former.

It is likewise known that this tendency to stain formation can beobviated by the utilization of reducing agents such as alkali sulfite,hydrazines, hydroxylamines and the like which operate to destroy theretained color developer. Rather peculiarly, it has been found that theaddition products referred to hereinabove are analogous to the reducingagents to the extent that both overcome the tendency to stain formation.Despite the factv that the addition products would not appear to beconstituted in a fashion to permit them to act as reducin agents, itwould, nevertheless, appear that they may have this property because ofthe results they achieve. In any case, the conclusion is inescapablethat the addition products either function as reducing agents to destroythe color developer, or react With the color developer or the oxidationproducts thereof in a manner to prevent subsequent reaction of the colordeveloper with retained color former.

The concentration of the addition products required may vary from aslittle as 0.5%, an amount which in general has been found to eliminatestain for the most part, to as much as 5%, an amount which is anassurance that stain formation will not ensue. Amounts higher than 5%give little improvement. Concentrations ranging from between 2 and 4%are most desirable from a commercial standpoint.

The photographic multi-layer materials, which may be processed with theanti-stain bath of the present invention, are color reversible film,color negative film, color reversible white printing material coated onan opaque base, and color positive printing material coated on paper,irrespective of whether the dyestuff images are produced with colorformers present in the emulsion, or by a selective second exposurefollowed by development with developing solutions containing colorformers and color developing agents.

The color reversible film consists of an integral tripack emulsioncoated on the usual clear cellulose acetate or nitrate film base. Eachof the emulsion are sensitized to one of the primary colors of light,namely, blue, green, and red. The top layer is blue sensitive. A filterlayer, yellow in color and blue absorbing, lies under the top layer.Below this filter layer, lies a green sensitive emulsion layer, andbelow this is a red sensitive emulsion layer. Each of the threesilver-halide emulsion layers contain dye-forming compounds which uniteduring the development of a silver image in an aromatic amine developingagent to form a dye with the oxidation product of the developing agent,or may be free from color formers in which case the film is processedwith the color formers in the color developers by the selective secondexposure and color development method as described in United StatesPatents 1,897,866, 1,900,870, 1,928,709 and 1,980,941.

As silver is formed during development, it must be removed after colordevelopment by treatment in a bleach, followed by treatment in a bath ofsodium thiosulfate, according to usual practice. A yellow dye is formedin the blue sensitive emulsion; a magenta dye is formed in the greensensitive emulsion; and a cyan dye is formed in the red sensitiveemulsion. Combinations of these 4 three printing primaries will produceall of the other colors in the finished film or print.

The color negative film is made up in the same: manner as the colorreversible film with the ex-- ception that it may contain a layer ofclear" gelatin between the red sensitive layer and the green sensitivelayer. The color reversible white opaque material is prepared in thesame manner as color reversible film and the color negative film withthe exception that the base consists of an opaque white film. The colorpaper is also constructed in the same manner as the color reversiblefilm and the color negative film, with the exception that the emulsionis coated on a baryta coated paper base. Suitable methods for thepreparation of photographic multi--layer materials have been describedin the literature relating to color photography and are, therefore, notdescribed here.

The following examples describe in detail. methods for accomplishing theabove objects, but it is to be understood that. they are inserted merelyfor purposes of illustration and are not to be construed as limiting thescope of the invention.

Example I A 4" x 5" full color transparency sheet of color." film wasprinted by contact on two 4" x 5" sheets of color reversible whiteopaque film.

The two sheets of 4" x 5" color reversible white opaque film were firstdeveloped for twelve minutes at 68 F. in a developer of the followingcomposition:

p-Monomethylaminephenol sulfate grams 3 Sodium sulfite do 50Hydroquinone do 6 Sodium carbonate (monohydrate) do 40 Sodiumthiocyanate do 2 Potassium bromide do 2 Water to make liter 1 Thedeveloped film was short stopped for three minutes at 68 F. in a 5%aqueous solution of sodium bisulfite.

The film was washed for two minutes in running water 68 F. andre-exposed to white light.

The re-exposed film was color developed for fifteen minutes at 68 F. ina developer of the following composition:

p-Aminodiethylaniline HCl grams 4 Sodium sulfite do 20 Hydroxylamine HCldo 2, Sodium carbonate do Potassium bromiden do 1 Water to make liter 1Di-potassium mono-sodium ferricyanide grams Potassium bromide do 15Disodium phosphate do 40 Sodium bisulfate do 25 Formalin (40%)s cubiccentimeters" 20 Water to make liter 1 'The bleached film was washed forfive minaromas utes at 68 F., and then fixed forfive minutes in asolution of the following composition:

Hypo grams 200 Borax do Water to make l-iter 1 water-soluble additionproduct of "formaldehyde methylol-cyanurtrihyand cyanurtrihydrazide,drazide, prepared according to Example I of United States Patent2,211,709, and then allowed to dry. At this point, the prints appearedidentical. After normal drying, the print'rinsed in the solutioncontaining the addition product of formaldehyde and cyanurtrihydrazideshowed brighter colors and more brilliant highlights. The print givenonly a water washing for five to twenty minutes showed a slighthighlight stain.

When the drying was carried out under conditions of high humidity sothat the drying time was extended for several hours, the water-rinsedprint showed even greater highlight stains While the print rinsed in theaqueous solution containing the addition product did not change.

After storing both prints, 1. e., treated and untreated for severalmonths, it was observed that the color balance of the treated print wasunaffected, whereas the color balance of the untreated print wascompletely ruined by yellow stain appearing overall, while at the sametime the densities of the original yellow image were lowered.

Example II Example III Example I was repeated with the exception thatthe colored material employed was a color transparency sheet and thefinal rinse bath consisted of 97 parts by weight of water and 3 parts byweight of a water-soluble addition product of formaldehyde and melamine,trimethylolmelamine, prepared according to Example VI of United StatesPatent 2,197,357. After fixing and washing, the color print washed inwater showed objectionable stains, while the color print treated withthe aqueous solution containing the addition product was clear andunstained.

Example IV Example I was repeated with the exception that the finalrinse consisted of 98 parts by weight of water and 2 parts by weight oftrimethylolmelamine available commercially under the brand name of "Ia-rial: MR1! and having the fol-lowing formula:

omen The color print washed inwater showed objectionable stains afterdrying, while the print treated with the solution containingthe-trimethylolmelamine was clear and unstained.

Similar results were obtained as in the preceding examples when theaddition products of Examples .2,- 4, and "5 of United States Patent2,211,709, Examples 3, 4, and 16 of United States Patent 2,211,710, andExamples 4, 7, and 15 of United States Patent 2,197,357 were employed.

The treated and untreated prints of Examples 11 to IV inclusive werestored for several months. The untreated prints showed marked stainingduring storage and the color balance after storage was completely ruinedby yellow stains, whereas no stains were evident on the treated printsand the color balance was unafiected.

Instead of employing the water-soluble addition products of formaldehydeand an azine in aqueous solutions as a final rinse bath, they may beincorporated into gelatin solutions in a concentration ranging from 25%and such gelatin solutions utilized as a surface coating for theprocessed multi-layer photographic material.

The above specific examples are to be regarded as being merelyillustrative of the invention and not in any sense restrictive. It willbe obvious to those skilled in the art that many modifications, such assubstituting equivalent materials and varying the proportions of thematerials used,

may be made. The scope of the invention is to be limited solely by theappended claims.

I claim:

1. In a process of producing color photographic images in asilver-halide emulsion by exposing the emulsion, color-formingdeveloping the same, bleaching, fixing, and washing, the improvementwhich comprises avoiding the formation of stain, after the bleaching andwashing operation, by rinsing the said silver-halide emulsion with anaqueous solution containing a water-soluble addition product offormaldehyde and an azine selected from the class consisting of thosehaving the following formulae:

wherein at least one Y is an amino group having at least one reactivehydrogen atom, the remaining Ys being a radical selected from the groupconsisting of hydrogen, hydroxyl, halogen, alkyl, alkylene, aryl andaralkyl, Z represents a member selected from the group consisting ofhydrogen amino, hydroxy, alkyl, alkoxy, phenyl, phenylene, mercapto,alkylthio and hydrazino, at least two Zs being a member selected fromthe class consisting of amino and hydrazino group,

X represents a member selected from the groupconsisting of hydrogen anda primary amino group, R represents a member of the group consisting ofhalogen, hydroxy, hydrazino, alkoxy, phenyl, and alkylthio groups.

2. In a process of producing color photographic images in asilver-halide emulsion by exposing the emulsion, color-formingdeveloping the same, bleaching, fixing, and washing, the improvementwhich comprises avoiding the formation of stain, after the bleaching andwashing operation, by rinsing the said silver-halide emulsion with anaqueous solution containing methylolcyanurtrihydrazide.

3. In a process of producing color photographic images in asilver-halide emulsion by exposing the emulsion, color-formingdeveloping the same,

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,384,658 Vittum Sept. 11, 19452.440.954 Jennings May 4, 1948

